Abstract
Simple anthocyanins are unstable in dilute aqueous solutions around pH 4-7, but some highly acylated anthocyanins were found to be stable in such solutions Structures of several highly acylated anthocyanins have been elucidated mainly by means of 1H-NMR including the NOE relief method. Stability of the anthocyanins has been assumed to come from intramolecular sandwich-type stacking of anthocyanidin nucleus and two aromatic acyl moieties.
